In radio communication devices represented by cellular phones, an LO (Local Oscillator) signal is used as a reference signal for modulation and demodulation. In recent years, multiple antennas, modulation circuits and demodulation circuits are provided (Multiple Input Multiple Output) to improve communication rate. Therefore, an area of a transmission and reception chip becomes larger, and thus, it becomes necessary to transmit the LO signal from a VCO (Voltage Controlled Oscillator) for generating the LO signal to the modulation circuit or demodulation circuit for a long distance.
Furthermore, it is desired for the radio communication devices to be compatible to a plurality of wireless standards. Accordingly, the radio communication devices should transmit and receive signals having various frequencies.